1. Field of the Invention
This invention relates to a self-crosslinking composition, a forming obtained from the composition, and a method for manufacturing the forming. More specifically, this invention relates to a self-crosslinking composition which crosslinks a polymer or elastomer which is crosslinked without using peroxide. According to prior art, a polymer or elastomer is crosslinked using a peroxide under a strict rejection of air. This invention also relates to a forming obtained from the composition, and to a method for manufacturing the forming.
2. Description of Related Art
The method for crosslinking using a peroxide, which is a crosslinking method using no sulfur, is applied to crosslink various types of elastomers and polymers excluding some of the polymers such as polyisobutylene. The crosslinking method using peroxide has the advantages of:
1) decreased scorch occurrence PA1 2) shorter crosslinking time PA1 3) superior in heat resistance and aging resistance PA1 4) less permanent compressive strain, and PA1 5) free from metal contamination caused by sulfur. PA1 1) being subjected to the effect of oxygen in air, which effect results in the non-existence of generated radicals, which then results in difficulty for crosslinking, PA1 2) inapplicability of process oil and anti-aging agents because they inhibit the crosslinking action of peroxide, which makes the selection of additives difficult, PA1 3) requiring a strict control of process conditions for conducting the crosslinking operation while rejecting air, (for example, when a Bambury mixer is used for kneading, the decomposition of added peroxide caused by generated heat and the accompanying crosslinking shall be prevented, also when the materials are fed to an extruder, an incorrect condition for treatment results in a solidification of polymer at the die opening, which induces serious trouble.) PA1 V=mesh-chain concentration (mol/cm.sup.3) PA1 RO.=concentration of organic peroxide radical (mol/cm.sup.3).
There are, however, the disadvantages of: